My depressed mother is ruining my life and relationship...?

Your mom has issues, and what she is doing to you is unfair. You are her son, and she should treat you like a son. She should put aside her feelings for your father and realize that you do need to have a relationship with him as well. Your mom is emotionally abusive. You don't deserve that. Tell your mom that until she starts seeing a therapist and dealing with her issues, you won't be able to see her. Then don't. Surely you have other family members in the area who can look in on her. Fill them in on the situation, let them know the truth as to why you are cutting mom out of your life. Talk to your dad about it, see if he can offer any help. You aren't giving up on your mother...you are forcing her to see that she has problems that she needs to fix. You are giving her tough love.